The 28-year-old was unveiled in front of the Emirates crowd ahead of their 3-2 pre-season friendly defeat to Borussia Dortmund on Sunday (August 9).
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Guimaraes signed for £75million from Newcastle and is the third new arrival of the summer, following Illan Meslier and Christos Tzolis.
Piero Hincapie also made his move from Bayer Leverkusen made permanent following an impressive loan last season, but Arsenal are still looking for more.
Asked if fans could expect further signings this summer after the game, Arteta replied: "Well that's what we're trying to do.
"If we have the right player in the market to make us much better, we are very looking forward to that."